This invention relates to a novel crystal form of xcex1,xcex1-dimethyl-4-{1-hydroxy4-{4-(hydroxydiphenylmethyl)-1-piperidinyl}butyl}benzeneacetic acid hydrochloride, a process for its preparation and pharmaceutical formulations thereof.
The compound xcex1,xcex1-dimethyl-4-{1-hydroxy-4-{4-(hydroxydiphenylmethyl)-1-piperidinyl}butyl}benzeneacetic acid hydrochloride has been named according to the U.S.A.N. as fexofenadine hydrochloride (xe2x80x9cF-HCIxe2x80x9d). It is known as the active metabolite of the non-sedating antihistamine terfinadine and is itself marketed in the United States as a non-sedating antihistamine. F-HCI and its preparation are described, for example, in U.S Pat. No. 5,578,610, which is here incorporated by reference. Anhydrous and hydrated crystal forms of F-HCI identified as Forms I, II, III and IV are described in WO 95/31437.
The present invention relates to a novel F-HCI crystal modification, hereinafter designated as Form A, which is distinguished from previously known crystal forms by physical and spectroscopic properties such as melting point, x-ray powder diffraction pattern, solid state NMR spectrum and infrared spectrum. The Form A crystal modification of F-HCI is prepared in an advantageously environmentally friendly manner.